Muffler and collector ring assembly for radial engines



y 1960 M. o. MILLER ETAL 2,936,845

MUFFLER AND COLLECTOR RING ASSEMBLY FOR RADIAL sncmzs Filed Oct. 31, 1955 f/IIIIIIIIIIIII FIG. I

INVENTORS 34 MERAL O. MILLER 3 JAMES L. MATHENY United s ais Pgt fl MUFFLER AND COLLECTOR RING ASSEMBLY FOR RADIAL ENGINES Meral 0. Miller, San Diego, and James L. Matheny, Santa Ana, Calif.; said Miller assignor of twenty-five percent to Thomas Ralph Snider, Orange County, and one percent to Western Inventers, San Diego, Cal|f., a corporation of California Application October 31, 1955, Serial No. 543,728 6 Claims. (Cl. 181-40) sound from each cylinder and thus constituting a combined collector ring and muffler with the functions of both retained and inter-related in a novel, highly eflicient manner.

Another object of this invention is to provide a contbined mufller and collector ring which can be used with existing radial engines without re-design of these engines.

Another object of this invention is to provide a muffier assembly for radial engines which is eflicient as such without creating unwanted back pressure in the engine.

Another object of this invention is to provide a muffler and collector ring assembly for radial engines which is adapted for fabrication from any diiferent materials, so that the choice of material canbe according to the dietates of availability and price considerations, the exact sizes and proportions being matters easily determined to suit particular conditions and needs.

Another object of this invention is to provide a mufiier and collector ring assembly for radial engines .which is practicable and inexpensive to manufacture.

Finally, it is an object to provide a collector ring of the aforementioned character which is simple, safe and convenient, to use and which will give generally efiicient and durable service.

With these and other objects definitely in view, this invention consists in the novel construction, combination and arrangement of elements and portions, as will be hereinafter fully described in the specification, particularly pointed out in the claims, and illustrated in the drawings which form a'material part of this disclosure, and in which: i 1

Figure 1 is a fragmentary cross-sectional view'of the device showing a portion of the collector ring, the mufiier casing with bafiie plates mounted therein, and a portion of the lead pipe for interconnection with an exhaust port.

Figure 2 is a front elevational view of the complete ring and rnufller assembly.

Figure 3 is a side elevational view of the complete ring and mufller assembly mounted on a radial engine, the engine being shown more or less diagrammatically.

Similar characters of reference indicate similar or identical elements and portions throughout the specification and throughout the views of the drawing.

In the following specification the instant invention will be assumed to be capable of replacing the conventional exhaust collector ring of an aircraft engine, and the axis 2,936,845 Patented May 17,

of the engine and collector ring will be assumed to be substantially horizontal with the collector ring'spaced slightly rearwardly of the engine.

Referring now to the drawings in detail, the muffler assembly comprises a sectional collectorring 10 having a plurality of interconnected sections '12. Each section 12 may be of circular cross section, or any other crosssectional shape required and is longitudinally arcuate, being provided with an inlet opening 14 on what will be referred to as the forward side thereof, that is, the side toward the engine. The inlet openings 14 are located on the sections 12 in such a manner as to assure misalignment of the openings 14 with the cylinders 24 of the engine somewhat diagrammatically illustrated in Figure 3. The misalignment of the openings 14 and the cylinders allows a mufller casing 20, communicating with each opening to lead into the collecting ring section 12 at an oblique angle. The casing 20 curves forwardly from the opening 14 and, in the unitary form represented best in Figure 1, is extended to constitute a lead pipe 22, the end of the lead pipe 22 remote from the opening 14 being attachable by means of a flange 23 to an engine cylinder 24. The bafiles are apertured centrally or, otherwise stated, the stub pipes extend through the baffles, but the stub pipes extend from the bafiles only on the upstream side of the battles. v

The mufller casing 20 is of the same size as the lead pipe 22 at the point of juncture thereof and increases rapidly in cross-sectional dimension toward the inlet opening 14.

Bafile plates 26 are vertically positioned within the mufiler'casing 20 and are provided with stub pipes 28 extending obliquely forward therefrom. The stub pipes 28 are fixed at an acute angle with the baffle plates in order to redirect the main stream of exhaust gases flowing therethroug'n from the horizontal direction of the lead pipe 22 to the vertical direction of the collector ring 10, with very little restriction to the fiow and, therefore very little increase in back pressure to the cylinder.

A dimple deformation 30 at the entrance to the mufiler casing 20 directs the exhaust gas toward the forwardly positioned stub pipe 28, through which the main stream of exhaust gases pass. The stub pipes 28 are of substantially the same cross: sectional dimensions as the lead'pipe 22, andthe stub pipes are aligned so that the axis of each stub pipe coincides as nearly as possible with the longitudinal center line of the casing 20, this center line being usually curved as inthe illustrated form of this invention. It will be clearly evident that this invention can be incorporated in casings which are rectilinear .or which have straight POI? tions while otherwise corresponding with the illustrated casing 20.

The incompletely closed spacesurrounding the pipes 28 constitutes a baflle chamber 32, into which a portion. of the exhaust gases expands. The expanded .gases' are guided in a circulatory path by the bafiieplates 26 an d the mufller casing 20 and re-enter the main exhaust stream at substantially right angles thereto. It will be evident that the bafiie chambers 32 closer to the collector ring 12 will be increased in volume over the preceding chambers 32 resulting in greater expansion of the gases and, therefore, also resulting in a slightly greater period of time required for the swirling gases to re-enter the main stream of gases flowing therethrough, thus assuring a slightly different frequency of pulsations in each chamber.

The flow of exhaust gases through the muffier system is intermittent and of a constant frequency for any given number of revolutions per minute of the engine 18. Therefore it will be evident that the frequency of pulsations in each bafiie chamber 32 will be slightly different from that of the main stream flowing therethrough and resonance is substantially eliminated. It is important to note that in operational tests the instant invention resulted in a substantial reduction in oil temperature while the back pressure to the cylinders was not materially increased. An outlet 34 directs the exhaust gases flowing through the collector ring 1 rearwardly of the engine. It will be obvious that the sections 12 of the ring need not be of constant cross-sectional dimension, but may be varied in accordance with the volume of gases to be vented and the cross-sectional shape may be circular in the majority of instances.

The general form of the muffler casings 20 will also vary with the location on the collector ring in order to best change the direction of flow of exhaust gases flowing therethrough. As illustrated in Figure 2, when necessary, a collector ring section 36 is provided with a casing corresponding generally with the casing 20 but expanded bilaterally at 38, 38 so that the flow of exhaust gases from the cylinder concerned is divided with a portion being directed to each half of the collectorring assembly 10. The collector ring section 40 illustrated in Figure 2 further shows how this invention is incorporated in a collector ring section required to service more than one cylinder of an engine and to provide an exhaust port, the section 40 having a pair of casings formed integral thereand a slightly different frequency of pulsation in said with and in spaced relation on each side of the collector ring exhaust outlet 34.

i The operation of this invention will be clearly comprehended from a consideration of the foregoing description of the mechanical details thereof, taken in connection with the drawing and the above recited objects. 'It will be obvious that all said objects are amply achieved by this invention.

Further description would appear to be unnecessary.

It is understood that minor variation from the form of the invention disclosed herein may be made without departure from the spirit and scope of the invention, and that the specification and drawing are to be considered as merely illustrative rather than limiting.

We claim:

1. A combined mufiler and collector ring assembly for a radial engine, comprising: a plurality of tubular sections of generally circular cross-section; said sections having means for interconnection to form a collector ring; an arcuate muffier casing on one side of each said sections; each of said casings having individual means of communication with an engine cylinder; and each of said mufiier casings having sound muffiing means therein comprising stub pipes spaced longitudinally of the mufiler casings and having their axes substantially coincident with the longitudinal central axis of the corresponding mufiler casing; bafile plates extending transversely of said mufiler casings and supporting said stub pipes; said stub pipes, baffles and adjacent portions of said casing generally defining chambers into which portions of an exhaust gas stream, passed through the muffler in the use thereof, expand and circulate; at least one baifie plate being a deflector guiding said portions of the exhaust gas stream to re-enter the main stream of the exhaust gas at substantially right angles thereto; said chambers being of varying volume so that there is a corresponding variation in the expansion of said portions chambers.

2. A combined muffler and collector ring assembly for a radial engine, comprising: a plurality of tubular sections of generally circular cross-section; said sections having means for interconnection to form a collector ring; an arcuate mufller casing on one side of each said sections; each of said casings having means of communication with an engine cylinder; and each of said arcuate mufiler casings having sound muffling means therein, comprising bafile plates disposed generally transversely of said arcuate mufiler casings; each of said baffie plates having a stub pipe extending upstream only therefrom, the axes of each stub pipe being substantially coincident with the arcuate longitudinal center line of the corresponding arcuate muflier casing.

3. A combined mufiler and collector ring assembly for a radial engine, comprising: a plurality of tubular sections of generally circular cross-section; said sectioi'is having means for interconnection to form a collector ring; a muffier casing on one side of each said sections; each of said casings having means of communication with an engine cylinder; and each of said casings having sound mufliing means therein; said muflling means comprising battle plates spaced longitudinally within said casing; said plates having stub pipes extending obliquely from the upstream side only of the bafile plates; and each of said stub pipes having its axis substantially coinciding with the longitudinal center line of said casing; said stub pipes in any one casing being obliquely disposed with respect to each other; one pair of said baflle plates and said casing defining at least one expansion chamber whereby a portion of the exhaust gases passing therethrough is deflected by that one of said baffle plates disposed downstream, circulated within said chamber, and directed by the other of said pair of baffle plates to re-enter into the main stream of the exhaust gases at right angles thereto.

4. A device according to claim 3 and including a dimple deformation in said casing, said deformation directing the flow of gases toward that one of said stub pipes disposed farthest upstream.

5. A device according to claim 3 and wherein said casings are larger in cross-sectional area at the ends thereof connected to said collector ring sections than at the other ends of the casings.

6. A device according to claim 5 wherein said casings are'arcuate.

References Cited in the file of this patent UNITED STATES PATENTS 1,332,663 Hassel Mar. 2, 1920 1,839,192 Baits Jan. 5, 1932 1,874,326 Mason Aug. 30, 1932 1,947,987 Hathorn Feb. 20, 19314 1,978,678 Kurth Oct. 30, 1934 2,206,259 Nield et al. July 2, 1940 2,280,953 Huntoon Apr. 28, 1942 FOREIGN PATENTS 9,335 Great Britain AD. 1911 210,488 Great Britain Feb. 7, 1924 

